What was the name of the battle where J.R.R. Tolkien served as a British Army signals officer in 1916?

J.R.R. Tolkien served as a British Army signals officer during the Battle of the Somme in 1916.

Tolkien was commissioned as a second lieutenant in the Lancashire Fusiliers after studying at Oxford and receiving military training. He went to France in June 1916 and served during the Somme offensive, one of the largest and bloodiest campaigns of the First World War.

He took part in the Battle of Thiepval Ridge and worked with communications responsibilities. In October 1916 he became ill with trench fever and was returned to England. The illness prevented him from continuing active service in France.

Tolkien later rejected simple one-to-one interpretations that treated his fiction as a direct allegory of the war. Nevertheless, his wartime experiences, the loss of close friends, and his knowledge of military life formed part of the historical background to his imagination. The Somme was fought from July to November 1916.